Humans in the Universe--Categories

I originally wanted to stay away from the
categorization of these essays. It is my believe that
categorization tends to separate and compartmentalize subjects in such a
way that they loose their connectiveness that enables us to understand
all of life as a whole. Ideally there would only be one category,
"Life." However, as the list of essays grew it became apparent
that some sort of categorization would be necessary. Some essays may
fit into several categories. Others may not fit well in any. In
the future they may need further division and separation, however for now,
we'll make do with what we have.